diff --git a/packages/protocol/contracts/signal/SignalService.sol b/packages/protocol/contracts/signal/SignalService.sol
index c8ceee1a91..5ffc9a1b4e 100644
--- a/packages/protocol/contracts/signal/SignalService.sol
+++ b/packages/protocol/contracts/signal/SignalService.sol
@@ -14,12 +14,8 @@
 
 pragma solidity 0.8.24;
 
-import "lib/openzeppelin-contracts/contracts/utils/math/SafeCast.sol";
 import "../common/EssentialContract.sol";
-import "../common/ICrossChainSync.sol";
 import "../libs/LibTrieProof.sol";
-import "../thirdparty/optimism/trie/SecureMerkleTrie.sol";
-import "../thirdparty/optimism/rlp/RLPReader.sol";
 import "./ISignalService.sol";
 import "./LibSignals.sol";
 
diff --git a/packages/protocol/test/TaikoTest.sol b/packages/protocol/test/TaikoTest.sol
index d1067d3049..f14f280c7a 100644
--- a/packages/protocol/test/TaikoTest.sol
+++ b/packages/protocol/test/TaikoTest.sol
@@ -4,6 +4,7 @@ pragma solidity 0.8.24;
 import "forge-std/Test.sol";
 import "forge-std/console2.sol";
 
+import "lib/openzeppelin-contracts/contracts/utils/math/SafeCast.sol";
 import "lib/openzeppelin-contracts/contracts/proxy/transparent/TransparentUpgradeableProxy.sol";
 
 import "../contracts/thirdparty/LibFixedPointMath.sol";